The sides of a quadrilateral measure 12 cm, 9 cm, 16 cm, 20 cm. The longest side of a similar quadrilateral measures 8 cm. What is the measure of the remaining sides of this quadrilateral?
a) 6 cm, 4.5 cm, 8 cm
b) 6 cm, 4.5 cm, 9.5 cm
c) 8 cm, 6 cm, 10.67 cm
d) 8 cm, 6 cm, 12 cm